// 原文：https://blog.csdn.net/qq_64608499/article/details/124990378
var possibleColors = ["#6db33f", "#14FFEC", "#00E0FF", "#FF99FE", "#FAF15D", "#f26d6d"]
var width = window.innerWidth;
var height = window.innerHeight;
var cursor = { x: width / 2, y: width / 2 };
var particles = [];

function init() {
    bindEvents();
    loop();
}

// Bind events that are needed
function bindEvents() {
    document.addEventListener('mousemove', onMouseMove);
    window.addEventListener('resize', onWindowResize);
}

function onWindowResize(e) {
    width = window.innerWidth;
    height = window.innerHeight;
}

function onMouseMove(e) {
    cursor.x = e.clientX;
    cursor.y = e.clientY;

    addParticle(cursor.x, cursor.y, possibleColors[Math.floor(Math.random() * possibleColors.length)]);
}

function addParticle(x, y, color) {
    var particle = new Particle();
    particle.init(x, y, color);
    particles.push(particle);
}

function updateParticles() {

    // Updated
    for (var i = 0; i < particles.length; i++) {
        particles[i].update();
    }

    // Remove dead particles
    for (var i = particles.length - 1; i >= 0; i--) {
        if (particles[i].lifeSpan < 0) {
            particles[i].die();
            particles.splice(i, 1);
        }
    }

}

function loop() {
    requestAnimationFrame(loop);
    updateParticles();
}

/**
 * Particles
 */
function Particle() {
    // 特效字符：https://shijianchuo.net/tesufuhao/
    //this.character = ['❥', '❤', '♥', '❣', '♫', '★', '☆', '※', '♡', 'ღ', '✪', '✯', '✿', '☃', '✬', '✵'];
    //this.character = ['✦', '✧', '♦', '♢', '✡', '◆', '◇'];
    this.character = ['✦', '✧'];
    this.lifeSpan = 120; //ms
    this.initialStyles = {
        "position": "fixed",
        "display": "inline-block",
        "top": "0px",
        "left": "0px",
        "pointerEvents": "none",
        "touch-action": "none",
        "z-index": "10000000",
        "fontSize": "25px",
        "will-change": "transform"
    };

    // Init, and set properties
    this.init = function (x, y, color) {

        this.velocity = {
            x: (Math.random() < 0.5 ? -1 : 1) * (Math.random() / 2),
            y: 1
        };

        this.position = { x: x + 10, y: y + 10 };
        this.initialStyles.color = color;

        this.element = document.createElement('span');
        this.element.innerHTML = this.character[Math.floor(Math.random() * (this.character.length - 1))];
        applyProperties(this.element, this.initialStyles);
        this.update();

        document.querySelector('.js-cursor-container').appendChild(this.element);
    };

    this.update = function () {
        this.position.x += this.velocity.x;
        this.position.y += this.velocity.y;
        this.lifeSpan--;

        this.element.style.transform = "translate3d(" + this.position.x + "px," + this.position.y + "px, 0) scale(" + (this.lifeSpan / 120) + ")";
    }

    this.die = function () {
        this.element.parentNode.removeChild(this.element);
    }

}

/**
 * Utils
 */
// Applies css `properties` to an element.
function applyProperties(target, properties) {
    for (var key in properties) {
        target.style[key] = properties[key];
    }
}

//if (!('ontouchstart' in window || navigator.msMaxTouchPoints)) init();

export function fairyDustCursor() {
    init();
}